FYSC has been involved in the testing and application development of the prototype rapid-scanning calorimeter introduced by TA Instruments (Delaware, USA) in 2007 (Project RHC). Currently, one of the 5 prototype instruments worldwide available is at operated at FYSC. The instrument can heat up and cool down at rates of up to 2500 K/min. In cooling a controlled cooling rate of 1000 K/min can be maintained between 300°C and 100°C, while a cooling rate of 250 K/min can be achieved down to -100°C.
The RHC sensor is about 6 mm long, the size of a conventional DSC pan, and is of the Tzero DSC type. RHC crucibles are about 1.5 mm diameter and 2 mm high. Typical sample masses are 250 to 500 µg.
Cooling samples at high rates can be used to avoid crystallization in cooling, while heating at high rates may prevent (undesirable) reorganization during heating. Among others, RHC proved to be especially useful to study the phase diagrams and crystallization kinetics of polymer:fullerene blends for solar cells, and for studying the melting of nanocomposites and electrospun nanofibres..
in collaboration with TA Instruments, Delaware, USA
Nanostructuring, morphological stability, and mechanism of charge transfer in conjugated polymer/fullerene blends for organic photovoltaic cells. An experimental and theoretical study
The aim of this project is to contribute to the fundamental insights into the mechanisms and criteria that affect the efficiency and stability of 'exciton' solar cells, based on the 'bulk heterojunction' concept. In this type of photovoltaic cells, foto-induced excitons (hole-electron pairs) that are formed in a donor phase of a phase separated system, must diffuse towards the (nano)interface ...
The goal of this project is to get insight in the fundamentals of the solution and phase behaviour of conjugated polymers in specific solvents, on the one hand, and to extend this knowledge to the rheological behaviour under shear or extension, on the other hand. This is extended from solutions of conducting polymers to mixtures of conjugated polymers with fullerene derivatives. These material ...